LGM-118A Peacekeeper

The Peacekeeper missile is America's newest intercontinental ballistic
missile. With the end of the Cold War, the US has begun to revise its
strategic policy, and has agreed to eliminate the multiple re-entry vehicle
Peacekeeper ICBMs by the year 2003 as part of the Strategic Arms Reduction
Treaty II. The Peacekeeper (designated LGM-118A) is a four-stage intercontinental ballistic missile capable of carrying up to ten independently-targetable reentry vehicles with greater accuracy than any other ballistic missile. Its design combines advanced technology in fuels, guidance, nozzle design, and motor construction with protection against the hostile nuclear environment associated with land-based systems. The Peacekeeper is much larger than Minuteman, over 70 feet long and weighing 198,000 pounds. It is a four stage missile like the Minuteman III, with the first three stages being solid propellant and the fourth stage bu hypergolicly fueled with hydrazine and nitrogen tetroxide. Although capable of carrying eleven Mark 21 RVs, treaty limits mandated deploying the Peacekeeper with only ten RVs.
The entire missile is encased in a canister in the silo to protect it against damage and to permit "cold launch". The Minuteman II and III ignite their first stage engines while in the LF, but the Peacekeeper is ejected by pressurized gas some fifty feet into the air before first stage ignition.

The Peacekeeper is a three-stage rocket ICBM system consisting of three major sections: the boost system, the post-boost vehicle system and the re-entry system.

The boost system consists of three rocket stages that launch the missile
into space. These rocket stages are mounted atop one another and fire successively. Three of the four stages exhausted
their solid propellants through a single adjustable nozzle which guided the missile along its flight
path. Motorcases made of kevlar epoxy material held the solid propellants. The fourth stage
post-boost vehicle employed a liquid bi- propellant rocket propulsion system to provide velocity and
attitude correction for missile guidance. The post-boost vehicle also employed a self-contained
inertial navigation system that allowed the missile to operate independent of ground reference or
commands during flight.

The 28-foot first-stage solid-fuel rocket motor weighed approximately 108,000 pounds and is
capable of boosting the missile to about 75,000 feet. The 18-foot long second-stage motor propelled
the missile to an altitude of about 190,000 feet and weighed 60,000 pounds. The rocket motor in the
eight-foot third stage weighed 17,000 pounds and supplied the thrust to boost the missile to about
700,000 feet. The 2,300 pound post-boost fourth stage vehicle was designed to maneuver the missile
into position for the multiple reentry vehicles to deploy in their respective ballistic trajectories.

Following the burnout and separation of the boost system's third rocket
stage, the post-boost vehicle system, in space, maneuvers the missile as
its re-entry vehicles are deployed in sequence.

The post-boost vehicle system is made up of a maneuvering rocket, and
a guidance and control system. The vehicle rides atop the boost system,
weighs about 3,000 pounds (1,363 kilograms) and is 4 feet (1.21 meters)
long.

The top section of the Peacekeeper is the re-entry system. It consists
of the deployment module, up to 10 cone-shaped re-entry vehicles and a protective
shroud. The shroud protects the re-entry vehicles during ascent. It is topped
with a nose cap, containing a rocket motor to separate it from the deployment
module.

The deployment module provides structural support for the re-entry vehicles
and carries the electronics needed to activate and deploy them. The vehicles
are covered with material to protect them during re-entry through the atmosphere
to their targets and are mechanically attached to the deployment module.
The attachments are unlatched by gas pressure from an explosive cartridge
broken by small, exploding bolts, which free the re-entry vehicles, allowing
them to separate from the deployment module with minimum disturbance. Each
deployed re-entry vehicle follows a ballistic path to its target.

The Peacekeeper was the first U.S. ICBM to use cold launch technology. The missile was placed
inside a canister and loaded into the launch facility. When launched, high-pressure steam ejected the canister from the launch silo to an altitude of 150 to 300 feet, and once the missile has cleared the
silo, the first stage ignited and sent the missile on its course. This technique allowed SAC to launch
the Peacekeeper from Minuteman silos despite the fact that the Peacekeeper was three times larger
than the Minuteman III.

Background

Once Minuteman III deloyment was underway, Strategic Air Command's planners began their search
for a third-generation ICBM. SAC again sought the most technologically advanced system to secure
increased range, variable warhead yields, and pinpoint accuracy. Several issues complicated the
development and acquisition of a new ICBM system. The increased accuracy of Soviet missile
systems spawned an intense debate over the survivability of fixed missile sites and the best method
for basing the third-generation ICBM. However, the issue of funding, given an atmosphere of
burgeoning federal deficits and cost-cutting measures, impeded SAC's efforts to acquire a new
missile. Nonetheless, SAC persevered and brought the Missile-X into the ICBM inventory as the
Peacekeeper missile.

The search for a system to replace the Minuteman began in 1971. Strategic Air Command, believing
Minuteman technology to be obsolete, wanted a new missile that incorporated the most advanced
technology available. Essential elements on SAC's list of requirements were increased range, greater
accuracy, and variable yield warheads to capitalize on multiple independently-targetable reentry
vehicle technology. Progress toward the new missile was made on 4 April 1972 when Headquarters
Air Force assigned the designation "Missile-X" (M-X) to the advanced ICBM and made the Space
and Missile Systems Organization (SAMSO) responsible for developing it.

The issue of hardened silos versus mobility surfaced almost immediately as a major M-X stumbling
point. Improvements in Soviet ICBM forces and missile accuracy raised serious concerns over the
ability of silo-based ICBMs to survive an attack. Proposed solutions to the problem were hardened
silos and a mobile basing system. Strategic Air Command objected to mobile basing in 1973 because
of its high expense, poor accuracy, and slow reaction time. Meanwhile, the defense community
continued to explore both solutions. One approach to mobility was an air-mobile system, and during
a 24 October 1974 test of the concept, SAMSO successfully launched a Minuteman I from a C-5A
cargo aircraft. One month later, the Secretary of Defense, under intense political pressure to resolve
basing issues and produce an economical missile system, pushed the M-X's initial operational
capability from 1983 to 1985. At the same time, he initiated studies to determine the feasibility of
developing a common M-X/Trident missile. In July 1976, Congress, convinced that silo-based
missiles would be vulnerable to Soviet ICBMs, refused to appropriate funds for validation of a silo-based M-X system. Congress also deleted funds for air-mobile basing and directed validation of
either a buried trench or shelter basing plan.

The defense establishment examined nearly forty basing modes before President Carter made his 12
June 1979 decision to proceed with full scale engineering development of the Missile-X. The
President augmented this decision on 7 September 1979 with the selection of a horizontal multiple
protective shelter basing plan for the new missile. Full scale engineering development began one
week later.

President Reagan, desiring more rapid deployment of the new missile, canceled the horizontal shelter
plan on 2 October 1981 and advocated the deployment of a limited number of M-X missiles in
superhardened Titan II or Minuteman silos. On 22 November 1982, the President further refined his
position by announcing Closely Spaced Basing as the final solution to the M-X basing problem.
President Reagan used the same speech to indicate his preference for "Peacekeeper" as the name of
the M-X missile. Congress, which had rejected interim Peacekeeper basing in Minuteman silos in

March 1982, also rejected Closely Spaced Basing and refused to approve Peacekeeper funding. The
Congress further insisted that the President undertake a comprehensive technical assessment of the
ICBM and basing alternatives.

President Reagan responded by first directing Headquarters Air Force to conduct a technical
assessment. The Air Force report, completed in March 1983, advocated deployment of a new, highly
accurate ICBM in sufficient numbers to eliminate the Soviet Union's "coercive advantage." The Air
Force also recommended concurrent deployment of a survivable basing method that allowed
credible, effective, and timely retaliation. A critical point in the Air Force assessment was the need
to deploy an ICBM quickly as a demonstration of national resolve to preserve deterrence.

President Reagan also appointed a Commission on Strategic Forces chaired by Lieutenant General
Brent Scowcroft. The Scowcroft Commission's report, issued on 6 April 1983, encouraged the
development of a small single-warhead ICBM to meet the long-range threat, but recommended the
immediate deployment of 100 Peacekeeper missiles in existing Minuteman silos to demonstrate
national will and to compensate for the retirement of Titan II ICBMs. The Scowcroft report also
encouraged a vigorous examination of all basing alternatives. President Reagan and Congress
concurred with the Scowcroft Commission's findings and on 10 August 1983 the Secretary of
Defense instructed the Air Force to deploy 100 Peacekeepers in Minuteman silos at F.E. Warren
AFB, Wyoming. At the same time, the Defense Secretary directed the Air Force to initiate design
of a small, single-warhead ICBM.

The Air Force successfully conducted the first test flight of the Peacekeeper
June 17, 1983, from Vandenberg Air Force Base, Calif. The missile traveled
4,190 miles (6,704 kilometers) before dropping six unarmed test re-entry
vehicles on planned target sites in the Kwajalein Missile Test Range in
the Pacific Ocean.

The first two test phases consisted of 12 test flights to ensure the
Peacekeeper's subsystems performed as planned, and to make final assessments
of its range and payload capability. The missile was fired from above-ground
canisters in its first eight tests. Thereafter, test flights were conducted
from Minuteman test silos reconfigured to simulate operational Peacekeeper
sites.

Peacekeeper production
began in February 1984. Under plans prepared by Strategic Air Command, 50 Minuteman IIIs
assigned to the 400th Strategic Missile Squadron, 90th Strategic Missile Wing, F.E. Warren AFB,
Wyoming, were be removed and replaced with Peacekeeper missiles, which had an estimated service
life of twenty years. Peacekeeper deployment was scheduled to begin in January 1986 and initial
operational capability was set for December of the same year. The second increment of 50 missiles
would replace Minuteman IIIs belonging to the 319th Strategic Missile Squadron at F.E. Warren.
The expected completion date of the deployment was December 1989.

These plans were interrupted in July 1985 when Congress limited Peacekeeper deployment to 50
missiles until the administration could produce a more survivable basing plan. President Reagan's
solution for basing the remaining 50 missiles, announced 19 December 1986, was Peacekeeper Rail
Garrison. Three days later, the 90th SMW achieved initial operational capability for Peacekeeper by
placing the first flight of ten missiles on strategic alert. Full operational capability occurred in
December 1988, when the 90th Strategic Missile Wing accepted the fiftieth Peacekeeper missile.

Under the rail garrison concept, the remaining Peacekeeper missiles would be placed on trains
stationed at various U.S. Air Force installations. The 25 trains, each carrying two missiles, would
deploy off-base and onto the national railroad network during periods of international tension to
improve survivability. F.E. Warren AFB would serve as the Main Operating Base for the rail
garrison force. In February 1987, the Air Force selected ten additional bases as candidate rail
garrison locations. That same year, Congress appropriated $350 million to fund rail garrison research
and development. Exercises conducted in 1988 tested and refined the concept of operations, and in
May the Secretary of Defense authorized the Air Force to proceed with Peacekeeper Rail Garrison
full scale development.

A further review of ICBM moderization produced a Presidential decision in April 1989 that limited
the Peacekeeper system to the existing 50 missiles but directed they be redeployed from silos to rail
garrison. In November, the Air Force announced the selection of seven bases to house Peacekeeper
Rail Garrison. The Main Operating Base would be F.E. Warren AFB, Wyoming, and the other six
bases were Barksdale AFB, Louisiana; Little Rock AFB, Arkansas; Grand Forks AFB, North
Dakota; Dyess AFB, Texas; Wurtsmith AFB, Michigan; and Fairchild AFB, Washington. December
1992 was the date established for delivery of the first asset.

The Air Force achieved initial operational capability of 10 deployed
Peacekeepers at F.E. Warren AFB, Wyo., in December 1986. Full operational
capability was achieved in December 1988 with the establishment of a squadron
of 50 missiles.

Ballistic Missile Organization, Air Force Materiel Command (now Detachment
10, Space and Missile Systems Center), began full-scale development of the
Peacekeeper in 1979. This organization, located at San Bernadino, Calif.,
integrated the activities of more than 27 civilian contractors and numerous
subcontractors to develop and build the Peacekeeper system.